Bonjour,
django-allauth has support for GitHub (with documentation). Although the GitHub URL can be replaced with the GITHUB_URL app setting, the API endpoint is hardcoded to be /api/v3 which won’t work with Gitea because it is /api/v1. A new Gitea provider should be created.
The Gitea OAuth2 provider endpoints are otherwise identical to the GitHub enpoints hardcoded in django-allauth.
Cheers